Power line communications (PLC) technology is aimed at transmitting digital data by utilizing the existing infrastructure of the electrical grid. It allows, in particular, remote reading of electric meters, exchanges between electric vehicles and the recharging terminals and also management and control of energy networks (smart grid). PLC technology incorporates, in particular, narrow band power line communication (N-PLC) which is generally defined as a communication over an electrical line operating at transmission frequencies of up to 500 KHz. N-PLC communication thus generally uses the frequency bands defined in particular by the European committee for electrotechnical standardization (CENELEC) or by the Federal Communications Commission (FCC). Thus, if the CENELEC A frequency band (3-95 kHz) is considered, the transmission frequencies are situated between 35.9375 and 90.625 KHz for the PLC-G3 standard.
The overall performance of a receiver greatly depends on the quality of its channel estimation, in other words of the estimation of the transfer function of this channel. It is known that a transmission channel can vary over time, in frequency, in phase, and in amplitude. Furthermore, the signals conveyed via PLC and received by the receiver result from a combination of several signals having taken several propagation paths within the transmission channel (i.e., the electrical power line), each having its own time delay and its own attenuation (the transmission channel is a multi-path transmission channel). This can then result in a significant attenuation of certain frequencies.
Furthermore, the properties and characteristics of electrical power grids are not a priori known and are variable over time. Thus, the impedances of certain objects connected by the user vary with the voltage. This is the case, for example, for halogen lamps or for objects comprising voltage rectifiers. When a user connects such objects, this then results in a variation of the transfer function of the transmission channel. The channel is then considered as linear and cyclostationary or linear and varying over time in a periodic manner, i.e. Linear Periodically Time Varying (LPTV). In other situations, the channel may be considered as linear and time invariant (LTI).